USB2504/USB2504A Data Sheet

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 2007 - 2016 Microchip Technology Inc.

DS000002250A-page 1

Highlights

• Integrated USB 2.0 Compatible 4-Port Hub

- 4 Transaction Translators for highest perfor-

mance 

- High-Speed (480Mbits/s), Full-Speed 

(12Mbits/s) and Low-Speed (1.5Mbits/s) 
compatible

- Full power management with per port or 

ganged, selectable power control

- Detects Bus-Power/Self-Power source and 

changes mode automatically

• Complete USB Specification 2.0 Compatibility

- Includes USB 2.0 Transceivers

• VID/PID/DID, and Port Configuration for Hub via:

- Single Serial I

2

C EEPROM

- SMBus Slave Port

• Default VID/PID/DID, allows functionality when 

configuration EEPROM is absent

• Hardware Strapping options allow for configura-

tion without an external EEPROM or SMBus Host

• On-Board 24MHz Crystal Driver Circuit or 24 MHz 

external clock driver

• Internal PLL for 480MHz USB 2.0 Sampling 

• Internal 1.8V Linear Voltage Regulator

• Integrated USB termination and Pull-up/Pull-down 

resistors

• Internal Short Circuit protection of USB differential 

signal pins

• 1.8 Volt Low Power Core Operation

• 3.3 Volt I/O with 5V Input Tolerance

• 64-Pin LQFP RoHS compliant package

USB2504/USB2504A

Integrated USB 2.0 Compatible 4-Port Hub

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USB2504/USB2504A

DS000002250A-page 2

 2007 - 2016 Microchip Technology Inc.

TO OUR VALUED CUSTOMERS

It is our intention to provide our valued customers with the best documentation possible to ensure successful use of your Microchip
products. To this end, we will continue to improve our publications to better suit your needs. Our publications will be refined and
enhanced as new volumes and updates are introduced. 

If you have any questions or comments regarding this publication, please contact the Marketing Communications Department via
E-mail at 

docerrors@microchip.com

. We welcome your feedback.

Most Current Data Sheet

To obtain the most up-to-date version of this data sheet, please register at our Worldwide Web site at:

http://www.microchip.com

You can determine the version of a data sheet by examining its literature number found on the bottom outside corner of any page. 
The last character of the literature number is the version number, (e.g., DS30000000A is version A of document DS30000000).

Errata

An errata sheet, describing minor operational differences from the data sheet and recommended workarounds, may exist for cur-
rent devices. As device/documentation issues become known to us, we will publish an errata sheet. The errata will specify the
revision of silicon and revision of document to which it applies.

To determine if an errata sheet exists for a particular device, please check with one of the following:
• Microchip’s Worldwide Web site; 

http://www.microchip.com

• Your local Microchip sales office (see last page)

When contacting a sales office, please specify which device, revision of silicon and data sheet (include -literature number) you are
using.

Customer Notification System

Register on our web site at 

www.microchip.com

 to receive the most current information on all of our products.

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 2007 - 2016 Microchip Technology Inc.

DS000002250A-page 3

USB2504/USB2504A

Table of Contents

1.0 Introduction  ..................................................................................................................................................................................... 4
2.0 Pin Table 4-Port  .............................................................................................................................................................................. 5
3.0 Pin Configuration 4-Port Hub  .......................................................................................................................................................... 6
4.0 4-Port Hub Block Diagram  .............................................................................................................................................................. 7
5.0 Functional Block Description ......................................................................................................................................................... 12
6.0 Backward Compatibility to the USB20H04 .................................................................................................................................... 30
7.0 XNOR Test .................................................................................................................................................................................... 31
8.0 DC Parameters  ............................................................................................................................................................................. 32
9.0 AC Specifications  .......................................................................................................................................................................... 36
10.0 Package Outline .......................................................................................................................................................................... 37
Appendix A: Data Sheet Revision History ........................................................................................................................................... 38
The Microchip Web Site  ...................................................................................................................................................................... 39
Customer Change Notification Service  ............................................................................................................................................... 39
Customer Support  ............................................................................................................................................................................... 39
Product Identification System  ............................................................................................................................................................. 40

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USB2504/USB2504A

DS000002250A-page 4

 2007 - 2016 Microchip Technology Inc.

1.0

INTRODUCTION

The Microchip 4-Port Hub is fully compliant with the USB 2.0 Specification and will attach to a USB host as a Full-Speed
Hub or as a Full-/High-Speed Hub. The 4-Port Hub supports Low-Speed, Full-Speed, and High-Speed (if operating as
a High-Speed Hub) downstream devices on all of the enabled downstream ports.

A dedicated Transaction Translator (TT) is available for each downstream facing port. This architecture ensures maxi-
mum USB throughput for each connected device when operating with mixed-speed peripherals. 

The Hub works with an external USB power distribution switch device to control V

BUS

 switching to downstream ports,

and to limit current and sense over-current conditions. 

All required resistors on the USB ports are integrated into the Hub. This includes all series termination resistors on D+
and D– pins and all required pull-down and pull-up resistors on D+ and D– pins. The over-current sense inputs for the
downstream facing ports have internal pull-up resistors.

Throughout this document the upstream facing port of the hub will be referred to as the upstream port, and the down-
stream facing ports will be called the downstream ports.

1.1

OEM Selectable Features

A default configuration is available in the USB2504/USB2504A following a reset. This configuration may be sufficient
for some applications. Strapping option pins make it possible to modify a limited sub-set of the configuration options. 

The USB2504/USB2504A may also be configured by an external EEPROM or a microcontroller. When using the micro-
controller interface, the Hub appears as an SMBus slave device. If the Hub is pin-strapped for external EEPROM con-
figuration but no external EEPROM is present, then a value of ‘0’ will be written to all configuration data bit fields (the
hub will attach to the host with all ‘0’ values).

The 4-Port Hub supports several OEM selectable features:

• Operation as a Self-Powered USB Hub or as a Bus-Powered USB Hub.

• Operation as a Dynamic-Powered Hub (Hub operates as a Bus-Powered device if a local power source is not 

available and switches to Self-Powered operation when a local power source is available).

• Multiple Transaction Translator (Multi-TT) or Single-TT support.

• Optional OEM configuration via I

2

C EEPROM or via the industry standard SMBus interface from an external 

SMBus Host.

• Port power switching on an individual or ganged basis.

• Port over-current monitoring on an individual or ganged basis.

• LED indicator support.

• Compound device support (port is permanently hardwired to a downstream USB peripheral device).

• Hardware strapping options enable configuration of the following features.

- Non-Removable Ports

- Port Power Polarity (active high or active low logic)

- Port Disable

- LED support

- MTT enable

- Ganged Vs Port power switching and over-current sensing

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 2007 - 2016 Microchip Technology Inc.

DS000002250A-page 5

USB2504/USB2504A

2.0

PIN TABLE 4-PORT

TABLE 2-1:

4-PORT PIN TABLE FOR 64-LQFP

UPSTREAM USB 2.0 INTERFACE (3 PINS)

USBDP0

USBDN0

VBUS_DET

4-PORT USB 2.0 INTERFACE (26 PINS)

USBDP1

USBDN1

USBDP2

USBDN2

USBDP3

USBDN3

USBDP4

USBDN4

GR1/

NON_REM0

GR2/

NON_REM1

GR3/

PRT_DIS0

GR4/

PRT_DIS1

AM1/

GANG_EN

AM2/

MTT_EN

AM3

AM4/

LED_EN

PRTPWR1

PRTPWR2

PRTPWR3

PRTPWR4

OCS1_N

OCS2_N

OCS3_N

OCS4_N

PRTPWR_POL

RBIAS

SERIAL PORT INTERFACE (5 PINS)

SDA/SMBDATA

SCL/SMBCLK/

CFG_SEL2

CFG_SEL1

CFG_SEL0

MISC (8 PINS)

XTAL1/CLKIN

XTAL2

RESET_N

SELF_PWR

ATEST/

REG_EN

CLKIN_EN

TEST1

TEST0

POWER, GROUND (17 PINS) AND (5) NO CONNECT

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USB2504/USB2504A

DS000002250A-page 6

 2007 - 2016 Microchip Technology Inc.

3.0

PIN CONFIGURATION 4-PORT HUB

FIGURE 3-1:

4-PORT 64-PIN LQFP

CFG_SEL1

RESET_N

SELF_PWR

VBUS_DET

VSS

VDD18

VSS

NC

XTAL2

TEST0

NC

VDD18

VSS

GR1/NON_REM0

VDD33

AM1/GANG_EN

GR2/NON_REM1

AM2/MTT_EN

OCS3

_

N

PRTP

W

R

2

OCS2

_

N

VDD1

8

VSS

CL

K

IN_EN

TE

ST

1

OCS1

_

N

PRTPW

R

1

USBDP0

VDDA33

USBDN0

VSS

USBDP1

USBDN1

VDDA3

3

USBDP2

USBDN2

USB2504 &
USB2504A

49

64

32

17

16

48

33

XTAL1/CLKIN

CFG_SEL2

VDDA18PLL

VSS

USBDN3

USBDP3

PRTPWR_POL

GR3/PRT_DIS0

AM3

PRTP

W

R

4

PRTPW

R

3

OCS4

_

N

VDDA33PLL

1

ATEST/REG_EN

RBIAS

VSS

VDDA33

USBDP4

USBDN4

VSS

GR4/PRT_DIS1

AM4/LED_EN

NC

NC

CFG_

SEL

0

NC

SCL/SMBCL

K

SDA/

S

M

BDATA

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 2007 - 2016 Microchip Technology Inc.

DS000002250A-page 1

Highlights

• Integrated USB 2.0 Compatible 4-Port Hub

- 4 Transaction Translators for highest perfor-

mance 

- High-Speed (480Mbits/s), Full-Speed 

(12Mbits/s) and Low-Speed (1.5Mbits/s) 
compatible

- Full power management with per port or 

ganged, selectable power control

- Detects Bus-Power/Self-Power source and 

changes mode automatically

• Complete USB Specification 2.0 Compatibility

- Includes USB 2.0 Transceivers

• VID/PID/DID, and Port Configuration for Hub via:

- Single Serial I

2

C EEPROM

- SMBus Slave Port

• Default VID/PID/DID, allows functionality when 

configuration EEPROM is absent

• Hardware Strapping options allow for configura-

tion without an external EEPROM or SMBus Host

• On-Board 24MHz Crystal Driver Circuit or 24 MHz 

external clock driver

• Internal PLL for 480MHz USB 2.0 Sampling 

• Internal 1.8V Linear Voltage Regulator

• Integrated USB termination and Pull-up/Pull-down 

resistors

• Internal Short Circuit protection of USB differential 

signal pins

• 1.8 Volt Low Power Core Operation

• 3.3 Volt I/O with 5V Input Tolerance

• 64-Pin LQFP RoHS compliant package

USB2504/USB2504A

Integrated USB 2.0 Compatible 4-Port Hub

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USB2504/USB2504A

DS000002250A-page 2

 2007 - 2016 Microchip Technology Inc.

TO OUR VALUED CUSTOMERS

It is our intention to provide our valued customers with the best documentation possible to ensure successful use of your Microchip
products. To this end, we will continue to improve our publications to better suit your needs. Our publications will be refined and
enhanced as new volumes and updates are introduced. 

If you have any questions or comments regarding this publication, please contact the Marketing Communications Department via
E-mail at 

docerrors@microchip.com

. We welcome your feedback.

Most Current Data Sheet

To obtain the most up-to-date version of this data sheet, please register at our Worldwide Web site at:

http://www.microchip.com

You can determine the version of a data sheet by examining its literature number found on the bottom outside corner of any page. 
The last character of the literature number is the version number, (e.g., DS30000000A is version A of document DS30000000).

Errata

An errata sheet, describing minor operational differences from the data sheet and recommended workarounds, may exist for cur-
rent devices. As device/documentation issues become known to us, we will publish an errata sheet. The errata will specify the
revision of silicon and revision of document to which it applies.

To determine if an errata sheet exists for a particular device, please check with one of the following:
• Microchip’s Worldwide Web site; 

http://www.microchip.com

• Your local Microchip sales office (see last page)

When contacting a sales office, please specify which device, revision of silicon and data sheet (include -literature number) you are
using.

Customer Notification System

Register on our web site at 

www.microchip.com

 to receive the most current information on all of our products.

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 2007 - 2016 Microchip Technology Inc.

DS000002250A-page 3

USB2504/USB2504A

Table of Contents

1.0 Introduction  ..................................................................................................................................................................................... 4
2.0 Pin Table 4-Port  .............................................................................................................................................................................. 5
3.0 Pin Configuration 4-Port Hub  .......................................................................................................................................................... 6
4.0 4-Port Hub Block Diagram  .............................................................................................................................................................. 7
5.0 Functional Block Description ......................................................................................................................................................... 12
6.0 Backward Compatibility to the USB20H04 .................................................................................................................................... 30
7.0 XNOR Test .................................................................................................................................................................................... 31
8.0 DC Parameters  ............................................................................................................................................................................. 32
9.0 AC Specifications  .......................................................................................................................................................................... 36
10.0 Package Outline .......................................................................................................................................................................... 37
Appendix A: Data Sheet Revision History ........................................................................................................................................... 38
The Microchip Web Site  ...................................................................................................................................................................... 39
Customer Change Notification Service  ............................................................................................................................................... 39
Customer Support  ............................................................................................................................................................................... 39
Product Identification System  ............................................................................................................................................................. 40

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USB2504/USB2504A

DS000002250A-page 4

 2007 - 2016 Microchip Technology Inc.

1.0

INTRODUCTION

The Microchip 4-Port Hub is fully compliant with the USB 2.0 Specification and will attach to a USB host as a Full-Speed
Hub or as a Full-/High-Speed Hub. The 4-Port Hub supports Low-Speed, Full-Speed, and High-Speed (if operating as
a High-Speed Hub) downstream devices on all of the enabled downstream ports.

A dedicated Transaction Translator (TT) is available for each downstream facing port. This architecture ensures maxi-
mum USB throughput for each connected device when operating with mixed-speed peripherals. 

The Hub works with an external USB power distribution switch device to control V

BUS

 switching to downstream ports,

and to limit current and sense over-current conditions. 

All required resistors on the USB ports are integrated into the Hub. This includes all series termination resistors on D+
and D– pins and all required pull-down and pull-up resistors on D+ and D– pins. The over-current sense inputs for the
downstream facing ports have internal pull-up resistors.

Throughout this document the upstream facing port of the hub will be referred to as the upstream port, and the down-
stream facing ports will be called the downstream ports.

1.1

OEM Selectable Features

A default configuration is available in the USB2504/USB2504A following a reset. This configuration may be sufficient
for some applications. Strapping option pins make it possible to modify a limited sub-set of the configuration options. 

The USB2504/USB2504A may also be configured by an external EEPROM or a microcontroller. When using the micro-
controller interface, the Hub appears as an SMBus slave device. If the Hub is pin-strapped for external EEPROM con-
figuration but no external EEPROM is present, then a value of ‘0’ will be written to all configuration data bit fields (the
hub will attach to the host with all ‘0’ values).

The 4-Port Hub supports several OEM selectable features:

• Operation as a Self-Powered USB Hub or as a Bus-Powered USB Hub.

• Operation as a Dynamic-Powered Hub (Hub operates as a Bus-Powered device if a local power source is not 

available and switches to Self-Powered operation when a local power source is available).

• Multiple Transaction Translator (Multi-TT) or Single-TT support.

• Optional OEM configuration via I

2

C EEPROM or via the industry standard SMBus interface from an external 

SMBus Host.

• Port power switching on an individual or ganged basis.

• Port over-current monitoring on an individual or ganged basis.

• LED indicator support.

• Compound device support (port is permanently hardwired to a downstream USB peripheral device).

• Hardware strapping options enable configuration of the following features.

- Non-Removable Ports

- Port Power Polarity (active high or active low logic)

- Port Disable

- LED support

- MTT enable

- Ganged Vs Port power switching and over-current sensing

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 2007 - 2016 Microchip Technology Inc.

DS000002250A-page 5

USB2504/USB2504A

2.0

PIN TABLE 4-PORT

TABLE 2-1:

4-PORT PIN TABLE FOR 64-LQFP

UPSTREAM USB 2.0 INTERFACE (3 PINS)

USBDP0

USBDN0

VBUS_DET

4-PORT USB 2.0 INTERFACE (26 PINS)

USBDP1

USBDN1

USBDP2

USBDN2

USBDP3

USBDN3

USBDP4

USBDN4

GR1/

NON_REM0

GR2/

NON_REM1

GR3/

PRT_DIS0

GR4/

PRT_DIS1

AM1/

GANG_EN

AM2/

MTT_EN

AM3

AM4/

LED_EN

PRTPWR1

PRTPWR2

PRTPWR3

PRTPWR4

OCS1_N

OCS2_N

OCS3_N

OCS4_N

PRTPWR_POL

RBIAS

SERIAL PORT INTERFACE (5 PINS)

SDA/SMBDATA

SCL/SMBCLK/

CFG_SEL2

CFG_SEL1

CFG_SEL0

MISC (8 PINS)

XTAL1/CLKIN

XTAL2

RESET_N

SELF_PWR

ATEST/

REG_EN

CLKIN_EN

TEST1

TEST0

POWER, GROUND (17 PINS) AND (5) NO CONNECT

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USB2504/USB2504A

DS000002250A-page 6

 2007 - 2016 Microchip Technology Inc.

3.0

PIN CONFIGURATION 4-PORT HUB

FIGURE 3-1:

4-PORT 64-PIN LQFP

CFG_SEL1

RESET_N

SELF_PWR

VBUS_DET

VSS

VDD18

VSS

NC

XTAL2

TEST0

NC

VDD18

VSS

GR1/NON_REM0

VDD33

AM1/GANG_EN

GR2/NON_REM1

AM2/MTT_EN

OCS3

_

N

PRTP

W

R

2

OCS2

_

N

VDD1

8

VSS

CL

K

IN_EN

TE

ST

1

OCS1

_

N

PRTPW

R

1

USBDP0

VDDA33

USBDN0

VSS

USBDP1

USBDN1

VDDA3

3

USBDP2

USBDN2

USB2504 &
USB2504A

49

64

32

17

16

48

33

XTAL1/CLKIN

CFG_SEL2

VDDA18PLL

VSS

USBDN3

USBDP3

PRTPWR_POL

GR3/PRT_DIS0

AM3

PRTP

W

R

4

PRTPW

R

3

OCS4

_

N

VDDA33PLL

1

ATEST/REG_EN

RBIAS

VSS

VDDA33

USBDP4

USBDN4

VSS

GR4/PRT_DIS1

AM4/LED_EN

NC

NC

CFG_

SEL

0

NC

SCL/SMBCL

K

SDA/

S

M

BDATA

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 2007 - 2016 Microchip Technology Inc.

DS000002250A-page 7

USB2504/USB2504A

4.0

4-PORT HUB BLOCK DIAGRAM

FIGURE 4-1:

4-PORT BLOCK DIAGRAM

TABLE 4-1:

4-PORT HUB PIN DESCRIPTIONS

Name

Symbol

Type

Function

UPSTREAM USB 2.0 INTERFACE

USB Bus Data

USBDN0

USBDP0

IO-U

These pins connect to the upstream USB bus data signals. 

Detect Upstream 

VBUS Power

VBUS_DET

I/O12

Detects state of Upstream VBUS power. The Microchip Hub 
monitors VBUS_DET to determine when to assert the internal 
D+ pull-up resistor (signaling a connect event). 

When designing a detachable hub, this pin must be 
connected to the VBUS power pin of the USB port that is 
upstream of the hub. (Use of a weak pull-down resistor is 
recommended.)

For self-powered applications with a permanently attached 
host, this pin must be pulled-up to either 3.3V or 5.0V 
(typically VDD33).

Upstream

V

BUS

Upstream

PHY

Upstream

USB Data

Repeater

Controller

SIE

Serial

Interface

PLL

24 MHz

Crystal

To

EEPROM

or SMBus

Master

Routing Logic

SCL

SD

TT

#1

TT

#2

TT

#3

TT

#4

Port

Controller

Downstream

PHY #1

Port #1

OC Sense

Switch Driver

LED Drivers

Downstream

PHY #4

Port #4

OC Sense

Switch Driver

LED Drivers

...

Downstream

USB Data

OC

Sense

Switch/LED

Drivers

Downstream

USB Data

OC

Sense

Switch/LED

Drivers

V

BUS

Power

Detect

Pin

Strapping

Options

Internal

Defaults

Select

3.3V

1.8V

Reg.

1.8V

Cap

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USB2504/USB2504A

DS000002250A-page 8

 2007 - 2016 Microchip Technology Inc.

4-PORT USB 2.0 HUB INTERFACE

High-Speed USB 

Data

USBDN[4:1]

USBDP[4:1]

IO-U

These pins connect to the downstream USB peripheral 
devices attached to the Hub’s ports. 

USB Power Enable

PRTPWR[4:1]

O12

Enables power to USB peripheral devices (downstream).

The active signal level of the PRTPWR[4:1] pins is 
determined by the Power Polarity Strapping function of the 
PRTPWR_POL pin.

Port 4:3 Green 

LED

&

Port Disable 

strapping option.

GR[4:3]/

PRT_DIS[1:0]

I/O12

Green indicator LED for ports 4 and 3. Will be active low 
when LED support is enabled via EEPROM or SMBus.

If the hub is configured by the internal default configuration, 
these pins will be sampled at RESET_N negation to 
determine if ports [4:2] will be permanently disabled. Also, the 
active state of the LED’s will be determined as follows:

PRT_DIS[1:0] = ‘00’, All ports are enabled, 
GR4 is active high,
GR3 is active high.

PRT_DIS[1:0] = ‘01’, Port 4 is disabled,
GR4 is active high,
GR3 is active low.

PRT_DIS[1:0] = ‘10’, Ports 4 & 3 are disabled,
GR4 is active low,
GR3 is active high.

PRT_DIS[1:0] = ‘11’, Ports 4, 3 & 2 are disabled,
GR4 is active low,
GR3 is active low.

Port [2:1] Green 

LED

&

Port Non-

Removable 

strapping option.

GR[2:1]/

NON_REM[1:0]

I/O12

Green indicator LED for ports 2 and 1. Will be active low 
when LED support is enabled via EEPROM or SMBus.

If the hub is configured by the internal default configuration, 
these pins will be sampled at RESET_N negation to 
determine if ports [3:1] contain permanently attached (non-
removable) devices. Also, the active state of the LED’s will be 
determined as follows:

NON_REM[1:0] = ‘00’, All ports are removable, 
GR2 is active high,
GR1 is active high.

NON_REM[1:0] = ‘01’, Port 1 is non-removable,
GR2 is active high,
GR1 is active low.

NON_REM[1:0] = ‘10’, Ports 1 & 2 are non-removable,
GR2 is active low,
GR1 is active high.

NON_REM[1:0] = ‘11’, Ports 1, 2, & 3 are non-removable,
GR2 is active low,
GR1 is active low.

Port 4 Amber LED

&

LED Enable 

strapping option

AM4/

LED_EN

I/O12

Amber indicator LED for port 4. Will be active low when LED 
support is enabled via EEPROM or SMBus.

If the hub is configured by the internal default configuration, 
this pin will be sampled at RESET_N negation to determine 
if LED support is enabled or disabled. Also, the active state 
of the LED will be determined as follows:

‘0’ = LED support is disabled, LED is inactive
‘1’ = LED Support is enabled, LED is active low.

TABLE 4-1:

4-PORT HUB PIN DESCRIPTIONS (CONTINUED) 

Name

Symbol

Type

Function

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USB2504/USB2504A

Port 3 Amber LED

AM3

I/O12

Amber indicator LED for port 3. Signal will be active low.

Port 2 Amber LED

&

MTT Disable

AM2/

MTT_EN

I/O12

Amber indicator LED for port 2. Will be active low when LED 
support is enabled via EEPROM or SMBus.

If the hub is configured by the internal default configuration, 
this pin will be sampled at RESET_N negation to determine 
if MTT support is disabled (STT only). Also, the active state 
of the LED will be determined as follows:

‘0’ = MTT support is disabled, LED is active high
‘1’ = MTT support is enabled, LED is active low.

Port 1 Amber LED

&

Gang Power 

Switching and 

Current Sensing 

strapping option.

AM1/

GANG_EN

I/O12

Amber indicator LED for port 1, Will be active low when LED 
support is enabled via EEPROM or SMBus.

If the hub is configured by the internal default configuration, 
this pin will be sampled at RESET_N negation to determine 
if downstream port power switching and current sensing are 
ganged, or individual port-by-port. Also, the active state of the 
LED will be determined as follows:

‘0’ = Port-by-port sensing & switching, LED is active high
‘1’ = Ganged sensing & switching, LED is active low.

Port Power Polarity 

strapping.

PRTPWR_POL

I/O12

Port Power Polarity strapping determination for the active 
signal polarity of the [4:1]PRTPWR pins. 

While RESET_N is asserted, the logic state of this pin will 
(though the use of internal combinatorial logic) determine the 
active state of the [4:1]PRTPWR pins in order to ensure that 
downstream port power is not inadvertently enabled to 
inactive ports during a hardware reset.

On the rising edge of RESET_N (see the applicable 
RESET_N timing table in 

Section 5.6.1

), the logic value will 

be latched internally, and will retain the active signal polarity 
for the PRTPWR[4:1] pins.

‘1’ = PRTPWR[4:1]_P/N pins have an active ‘high’ polarity
‘0’ = PRTPWR[4:1]_P/N pins have an active ‘low’ polarity

Over Current 

Sense

OCS[4:1]_N

IPU

Input from external current monitor indicating an over-current 
condition. {Note: Contains internal pull-up to 3.3V supply}

USB Transceiver 

Bias

RBIAS

I-R

A 12.0k

 (resistor is attached from ground to this pin 

to set the transceiver’s internal bias settings.

SERIAL PORT INTERFACE

Serial Data/SMB 

Data

SDA/SMBDATA

IOSD12

(Serial Data)/(SMB Data) signal.

Serial Clock/SMB 

Clock 

SCL/SMBCLK

IOSD12

(Serial Clock)/(SMB Clock) signal. 

Configuration 

Programming 

Select

CFG_SEL0

IOSD12

This multifunction pin is read on the rising edge of RESET_N 
negation and will determine the hub configuration method as 
described in 

Table 4-2

.

Configuration 

Programming 

Select

CFG_SEL1

I

This pin is read on the rising edge of RESET_N (see the 
applicable RESET_N timing table in 

Section 5.6.1

) and will 

determine the hub configuration method as described in 

Table 4-2

.

Configuration 

Programming 

Select

CFG_SEL2

I

This pin is read on the rising edge of RESET_N negation and 
will determine the hub configuration method as described in 

Table 4-2

.

TABLE 4-1:

4-PORT HUB PIN DESCRIPTIONS (CONTINUED) 

Name

Symbol

Type

Function

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TABLE 4-2:

SMBUS OR EEPROM INTERFACE BEHAVIOR

CFG_SEL2

CFG_SEL1

CFG_SEL0

SMBus or EEPROM Interface Behavior

X

0

0

Configured as an SMBus slave for external download of user-
defined descriptors. SMBus slave address is 0101100

X

0

1

Configured as an SMBus slave for external download of user-
defined descriptors. SMBus slave address is 0101101

0

1

0

Internal Default Configuration

1

1

0

Internal Default Configuration via strapping options.

X

1

1

2-wire (I

2

C) EEPROMS are supported,

TABLE 4-3:

MISCELLANEOUS PINS

Name

Symbol

Type

Function

Crystal 

Input/External 

Clock Input

XTAL1/

CLKIN

ICLKx

24MHz crystal or external clock input.
This pin connects to either one terminal of the crystal or to 
an external 24MHz clock when a crystal is not used.

Crystal Output

XTAL2

OCLKx

24MHz Crystal
This is the other terminal of the crystal, or left unconnected 
when an external clock source is used to drive 
XTAL1/CLKIN. It must not be used to drive any external 
circuitry other than the crystal circuit.

Clock Input 

Enable

CLKIN_EN

I

Clock In Enable:
Low = XTAL1 and XTAL2 pins configured for use with 
external crystal
High = XTAL1 pin configured as CLKIN, and must be 
driven by an external CMOS clock.

RESET Input

RESET_N

IS

This active low signal is used by the system to reset the 
chip. The minimum active low pulse is 1us.

Self-Power / 

Bus-Power 

Detect

SELF_PWR

I

Detects availability of local self-power source.
Low = Self/local power source is NOT available (i.e., Hub 
gets all power from Upstream USB VBus).
High = Self/local power source is available.

TEST Pins

TEST[1:0]

IPD

Used for testing the chip. User must treat as a no-connect 
or connect to ground.

Analog Test

&

Internal 1.8V 

voltage regulator 

enable

ATEST/

REG_EN

AIO

This signal is used for testing the analog section of the 
chip, and to enable or disable the internal 1.8v regulator. 

This pin must be connected to VDDA33 to enable the 
internal 1.8V regulator, or to VSS to disable the internal 
regulator.

When the internal regulator is enabled, the 1.8V power 
pins must be left unconnected, except for the required 
bypass capacitors.When the PHY is in test mode, the 
internal regulator is disabled and the ATEST pin functions 
as a test pin.

TABLE 4-4:

POWER, GROUND, AND NO CONNECT

Name

Symbol

Type

Function

VDD1P8

VDD18

+1.8V core power.

If the internal regulator is enabled, then VDD18 pin 54 
must have a 4.7

F (or greater) ±20% (ESR <0.1



capacitor to VSS

VDDAPLL3P3

VDDA33PLL

+3.3V Filtered analog power for the internal PLL

If the internal PLL 1.8V regulator is enabled, then this pin 
acts as the regulator input

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 2007 - 2016 Microchip Technology Inc.

DS000002250A-page 1

Highlights

• Integrated USB 2.0 Compatible 4-Port Hub

- 4 Transaction Translators for highest perfor-

mance 

- High-Speed (480Mbits/s), Full-Speed 

(12Mbits/s) and Low-Speed (1.5Mbits/s) 
compatible

- Full power management with per port or 

ganged, selectable power control

- Detects Bus-Power/Self-Power source and 

changes mode automatically

• Complete USB Specification 2.0 Compatibility

- Includes USB 2.0 Transceivers

• VID/PID/DID, and Port Configuration for Hub via:

- Single Serial I

2

C EEPROM

- SMBus Slave Port

• Default VID/PID/DID, allows functionality when 

configuration EEPROM is absent

• Hardware Strapping options allow for configura-

tion without an external EEPROM or SMBus Host

• On-Board 24MHz Crystal Driver Circuit or 24 MHz 

external clock driver

• Internal PLL for 480MHz USB 2.0 Sampling 

• Internal 1.8V Linear Voltage Regulator

• Integrated USB termination and Pull-up/Pull-down 

resistors

• Internal Short Circuit protection of USB differential 

signal pins

• 1.8 Volt Low Power Core Operation

• 3.3 Volt I/O with 5V Input Tolerance

• 64-Pin LQFP RoHS compliant package

USB2504/USB2504A

Integrated USB 2.0 Compatible 4-Port Hub

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USB2504/USB2504A

DS000002250A-page 2

 2007 - 2016 Microchip Technology Inc.

TO OUR VALUED CUSTOMERS

It is our intention to provide our valued customers with the best documentation possible to ensure successful use of your Microchip
products. To this end, we will continue to improve our publications to better suit your needs. Our publications will be refined and
enhanced as new volumes and updates are introduced. 

If you have any questions or comments regarding this publication, please contact the Marketing Communications Department via
E-mail at 

docerrors@microchip.com

. We welcome your feedback.

Most Current Data Sheet

To obtain the most up-to-date version of this data sheet, please register at our Worldwide Web site at:

http://www.microchip.com

You can determine the version of a data sheet by examining its literature number found on the bottom outside corner of any page. 
The last character of the literature number is the version number, (e.g., DS30000000A is version A of document DS30000000).

Errata

An errata sheet, describing minor operational differences from the data sheet and recommended workarounds, may exist for cur-
rent devices. As device/documentation issues become known to us, we will publish an errata sheet. The errata will specify the
revision of silicon and revision of document to which it applies.

To determine if an errata sheet exists for a particular device, please check with one of the following:
• Microchip’s Worldwide Web site; 

http://www.microchip.com

• Your local Microchip sales office (see last page)

When contacting a sales office, please specify which device, revision of silicon and data sheet (include -literature number) you are
using.

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Register on our web site at 

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 to receive the most current information on all of our products.

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 2007 - 2016 Microchip Technology Inc.

DS000002250A-page 3

USB2504/USB2504A

Table of Contents

1.0 Introduction  ..................................................................................................................................................................................... 4
2.0 Pin Table 4-Port  .............................................................................................................................................................................. 5
3.0 Pin Configuration 4-Port Hub  .......................................................................................................................................................... 6
4.0 4-Port Hub Block Diagram  .............................................................................................................................................................. 7
5.0 Functional Block Description ......................................................................................................................................................... 12
6.0 Backward Compatibility to the USB20H04 .................................................................................................................................... 30
7.0 XNOR Test .................................................................................................................................................................................... 31
8.0 DC Parameters  ............................................................................................................................................................................. 32
9.0 AC Specifications  .......................................................................................................................................................................... 36
10.0 Package Outline .......................................................................................................................................................................... 37
Appendix A: Data Sheet Revision History ........................................................................................................................................... 38
The Microchip Web Site  ...................................................................................................................................................................... 39
Customer Change Notification Service  ............................................................................................................................................... 39
Customer Support  ............................................................................................................................................................................... 39
Product Identification System  ............................................................................................................................................................. 40

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USB2504/USB2504A

DS000002250A-page 4

 2007 - 2016 Microchip Technology Inc.

1.0

INTRODUCTION

The Microchip 4-Port Hub is fully compliant with the USB 2.0 Specification and will attach to a USB host as a Full-Speed
Hub or as a Full-/High-Speed Hub. The 4-Port Hub supports Low-Speed, Full-Speed, and High-Speed (if operating as
a High-Speed Hub) downstream devices on all of the enabled downstream ports.

A dedicated Transaction Translator (TT) is available for each downstream facing port. This architecture ensures maxi-
mum USB throughput for each connected device when operating with mixed-speed peripherals. 

The Hub works with an external USB power distribution switch device to control V

BUS

 switching to downstream ports,

and to limit current and sense over-current conditions. 

All required resistors on the USB ports are integrated into the Hub. This includes all series termination resistors on D+
and D– pins and all required pull-down and pull-up resistors on D+ and D– pins. The over-current sense inputs for the
downstream facing ports have internal pull-up resistors.

Throughout this document the upstream facing port of the hub will be referred to as the upstream port, and the down-
stream facing ports will be called the downstream ports.

1.1

OEM Selectable Features

A default configuration is available in the USB2504/USB2504A following a reset. This configuration may be sufficient
for some applications. Strapping option pins make it possible to modify a limited sub-set of the configuration options. 

The USB2504/USB2504A may also be configured by an external EEPROM or a microcontroller. When using the micro-
controller interface, the Hub appears as an SMBus slave device. If the Hub is pin-strapped for external EEPROM con-
figuration but no external EEPROM is present, then a value of ‘0’ will be written to all configuration data bit fields (the
hub will attach to the host with all ‘0’ values).

The 4-Port Hub supports several OEM selectable features:

• Operation as a Self-Powered USB Hub or as a Bus-Powered USB Hub.

• Operation as a Dynamic-Powered Hub (Hub operates as a Bus-Powered device if a local power source is not 

available and switches to Self-Powered operation when a local power source is available).

• Multiple Transaction Translator (Multi-TT) or Single-TT support.

• Optional OEM configuration via I

2

C EEPROM or via the industry standard SMBus interface from an external 

SMBus Host.

• Port power switching on an individual or ganged basis.

• Port over-current monitoring on an individual or ganged basis.

• LED indicator support.

• Compound device support (port is permanently hardwired to a downstream USB peripheral device).

• Hardware strapping options enable configuration of the following features.

- Non-Removable Ports

- Port Power Polarity (active high or active low logic)

- Port Disable

- LED support

- MTT enable

- Ganged Vs Port power switching and over-current sensing

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 2007 - 2016 Microchip Technology Inc.

DS000002250A-page 5

USB2504/USB2504A

2.0

PIN TABLE 4-PORT

TABLE 2-1:

4-PORT PIN TABLE FOR 64-LQFP

UPSTREAM USB 2.0 INTERFACE (3 PINS)

USBDP0

USBDN0

VBUS_DET

4-PORT USB 2.0 INTERFACE (26 PINS)

USBDP1

USBDN1

USBDP2

USBDN2

USBDP3

USBDN3

USBDP4

USBDN4

GR1/

NON_REM0

GR2/

NON_REM1

GR3/

PRT_DIS0

GR4/

PRT_DIS1

AM1/

GANG_EN

AM2/

MTT_EN

AM3

AM4/

LED_EN

PRTPWR1

PRTPWR2

PRTPWR3

PRTPWR4

OCS1_N

OCS2_N

OCS3_N

OCS4_N

PRTPWR_POL

RBIAS

SERIAL PORT INTERFACE (5 PINS)

SDA/SMBDATA

SCL/SMBCLK/

CFG_SEL2

CFG_SEL1

CFG_SEL0

MISC (8 PINS)

XTAL1/CLKIN

XTAL2

RESET_N

SELF_PWR

ATEST/

REG_EN

CLKIN_EN

TEST1

TEST0

POWER, GROUND (17 PINS) AND (5) NO CONNECT

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USB2504/USB2504A

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 2007 - 2016 Microchip Technology Inc.

3.0

PIN CONFIGURATION 4-PORT HUB

FIGURE 3-1:

4-PORT 64-PIN LQFP

CFG_SEL1

RESET_N

SELF_PWR

VBUS_DET

VSS

VDD18

VSS

NC

XTAL2

TEST0

NC

VDD18

VSS

GR1/NON_REM0

VDD33

AM1/GANG_EN

GR2/NON_REM1

AM2/MTT_EN

OCS3

_

N

PRTP

W

R

2

OCS2

_

N

VDD1

8

VSS

CL

K

IN_EN

TE

ST

1

OCS1

_

N

PRTPW

R

1

USBDP0

VDDA33

USBDN0

VSS

USBDP1

USBDN1

VDDA3

3

USBDP2

USBDN2

USB2504 &
USB2504A

49

64

32

17

16

48

33

XTAL1/CLKIN

CFG_SEL2

VDDA18PLL

VSS

USBDN3

USBDP3

PRTPWR_POL

GR3/PRT_DIS0

AM3

PRTP

W

R

4

PRTPW

R

3

OCS4

_

N

VDDA33PLL

1

ATEST/REG_EN

RBIAS

VSS

VDDA33

USBDP4

USBDN4

VSS

GR4/PRT_DIS1

AM4/LED_EN

NC

NC

CFG_

SEL

0

NC

SCL/SMBCL

K

SDA/

S

M

BDATA

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DS000002250A-page 7

USB2504/USB2504A

4.0

4-PORT HUB BLOCK DIAGRAM

FIGURE 4-1:

4-PORT BLOCK DIAGRAM

TABLE 4-1:

4-PORT HUB PIN DESCRIPTIONS

Name

Symbol

Type

Function

UPSTREAM USB 2.0 INTERFACE

USB Bus Data

USBDN0

USBDP0

IO-U

These pins connect to the upstream USB bus data signals. 

Detect Upstream 

VBUS Power

VBUS_DET

I/O12

Detects state of Upstream VBUS power. The Microchip Hub 
monitors VBUS_DET to determine when to assert the internal 
D+ pull-up resistor (signaling a connect event). 

When designing a detachable hub, this pin must be 
connected to the VBUS power pin of the USB port that is 
upstream of the hub. (Use of a weak pull-down resistor is 
recommended.)

For self-powered applications with a permanently attached 
host, this pin must be pulled-up to either 3.3V or 5.0V 
(typically VDD33).

Upstream

V

BUS

Upstream

PHY

Upstream

USB Data

Repeater

Controller

SIE

Serial

Interface

PLL

24 MHz

Crystal

To

EEPROM

or SMBus

Master

Routing Logic

SCL

SD

TT

#1

TT

#2

TT

#3

TT

#4

Port

Controller

Downstream

PHY #1

Port #1

OC Sense

Switch Driver

LED Drivers

Downstream

PHY #4

Port #4

OC Sense

Switch Driver

LED Drivers

...

Downstream

USB Data

OC

Sense

Switch/LED

Drivers

Downstream

USB Data

OC

Sense

Switch/LED

Drivers

V

BUS

Power

Detect

Pin

Strapping

Options

Internal

Defaults

Select

3.3V

1.8V

Reg.

1.8V

Cap

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USB2504/USB2504A

DS000002250A-page 8

 2007 - 2016 Microchip Technology Inc.

4-PORT USB 2.0 HUB INTERFACE

High-Speed USB 

Data

USBDN[4:1]

USBDP[4:1]

IO-U

These pins connect to the downstream USB peripheral 
devices attached to the Hub’s ports. 

USB Power Enable

PRTPWR[4:1]

O12

Enables power to USB peripheral devices (downstream).

The active signal level of the PRTPWR[4:1] pins is 
determined by the Power Polarity Strapping function of the 
PRTPWR_POL pin.

Port 4:3 Green 

LED

&

Port Disable 

strapping option.

GR[4:3]/

PRT_DIS[1:0]

I/O12

Green indicator LED for ports 4 and 3. Will be active low 
when LED support is enabled via EEPROM or SMBus.

If the hub is configured by the internal default configuration, 
these pins will be sampled at RESET_N negation to 
determine if ports [4:2] will be permanently disabled. Also, the 
active state of the LED’s will be determined as follows:

PRT_DIS[1:0] = ‘00’, All ports are enabled, 
GR4 is active high,
GR3 is active high.

PRT_DIS[1:0] = ‘01’, Port 4 is disabled,
GR4 is active high,
GR3 is active low.

PRT_DIS[1:0] = ‘10’, Ports 4 & 3 are disabled,
GR4 is active low,
GR3 is active high.

PRT_DIS[1:0] = ‘11’, Ports 4, 3 & 2 are disabled,
GR4 is active low,
GR3 is active low.

Port [2:1] Green 

LED

&

Port Non-

Removable 

strapping option.

GR[2:1]/

NON_REM[1:0]

I/O12

Green indicator LED for ports 2 and 1. Will be active low 
when LED support is enabled via EEPROM or SMBus.

If the hub is configured by the internal default configuration, 
these pins will be sampled at RESET_N negation to 
determine if ports [3:1] contain permanently attached (non-
removable) devices. Also, the active state of the LED’s will be 
determined as follows:

NON_REM[1:0] = ‘00’, All ports are removable, 
GR2 is active high,
GR1 is active high.

NON_REM[1:0] = ‘01’, Port 1 is non-removable,
GR2 is active high,
GR1 is active low.

NON_REM[1:0] = ‘10’, Ports 1 & 2 are non-removable,
GR2 is active low,
GR1 is active high.

NON_REM[1:0] = ‘11’, Ports 1, 2, & 3 are non-removable,
GR2 is active low,
GR1 is active low.

Port 4 Amber LED

&

LED Enable 

strapping option

AM4/

LED_EN

I/O12

Amber indicator LED for port 4. Will be active low when LED 
support is enabled via EEPROM or SMBus.

If the hub is configured by the internal default configuration, 
this pin will be sampled at RESET_N negation to determine 
if LED support is enabled or disabled. Also, the active state 
of the LED will be determined as follows:

‘0’ = LED support is disabled, LED is inactive
‘1’ = LED Support is enabled, LED is active low.

TABLE 4-1:

4-PORT HUB PIN DESCRIPTIONS (CONTINUED) 

Name

Symbol

Type

Function

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 2007 - 2016 Microchip Technology Inc.

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USB2504/USB2504A

Port 3 Amber LED

AM3

I/O12

Amber indicator LED for port 3. Signal will be active low.

Port 2 Amber LED

&

MTT Disable

AM2/

MTT_EN

I/O12

Amber indicator LED for port 2. Will be active low when LED 
support is enabled via EEPROM or SMBus.

If the hub is configured by the internal default configuration, 
this pin will be sampled at RESET_N negation to determine 
if MTT support is disabled (STT only). Also, the active state 
of the LED will be determined as follows:

‘0’ = MTT support is disabled, LED is active high
‘1’ = MTT support is enabled, LED is active low.

Port 1 Amber LED

&

Gang Power 

Switching and 

Current Sensing 

strapping option.

AM1/

GANG_EN

I/O12

Amber indicator LED for port 1, Will be active low when LED 
support is enabled via EEPROM or SMBus.

If the hub is configured by the internal default configuration, 
this pin will be sampled at RESET_N negation to determine 
if downstream port power switching and current sensing are 
ganged, or individual port-by-port. Also, the active state of the 
LED will be determined as follows:

‘0’ = Port-by-port sensing & switching, LED is active high
‘1’ = Ganged sensing & switching, LED is active low.

Port Power Polarity 

strapping.

PRTPWR_POL

I/O12

Port Power Polarity strapping determination for the active 
signal polarity of the [4:1]PRTPWR pins. 

While RESET_N is asserted, the logic state of this pin will 
(though the use of internal combinatorial logic) determine the 
active state of the [4:1]PRTPWR pins in order to ensure that 
downstream port power is not inadvertently enabled to 
inactive ports during a hardware reset.

On the rising edge of RESET_N (see the applicable 
RESET_N timing table in 

Section 5.6.1

), the logic value will 

be latched internally, and will retain the active signal polarity 
for the PRTPWR[4:1] pins.

‘1’ = PRTPWR[4:1]_P/N pins have an active ‘high’ polarity
‘0’ = PRTPWR[4:1]_P/N pins have an active ‘low’ polarity

Over Current 

Sense

OCS[4:1]_N

IPU

Input from external current monitor indicating an over-current 
condition. {Note: Contains internal pull-up to 3.3V supply}

USB Transceiver 

Bias

RBIAS

I-R

A 12.0k

 (resistor is attached from ground to this pin 

to set the transceiver’s internal bias settings.

SERIAL PORT INTERFACE

Serial Data/SMB 

Data

SDA/SMBDATA

IOSD12

(Serial Data)/(SMB Data) signal.

Serial Clock/SMB 

Clock 

SCL/SMBCLK

IOSD12

(Serial Clock)/(SMB Clock) signal. 

Configuration 

Programming 

Select

CFG_SEL0

IOSD12

This multifunction pin is read on the rising edge of RESET_N 
negation and will determine the hub configuration method as 
described in 

Table 4-2

.

Configuration 

Programming 

Select

CFG_SEL1

I

This pin is read on the rising edge of RESET_N (see the 
applicable RESET_N timing table in 

Section 5.6.1

) and will 

determine the hub configuration method as described in 

Table 4-2

.

Configuration 

Programming 

Select

CFG_SEL2

I

This pin is read on the rising edge of RESET_N negation and 
will determine the hub configuration method as described in 

Table 4-2

.

TABLE 4-1:

4-PORT HUB PIN DESCRIPTIONS (CONTINUED) 

Name

Symbol

Type

Function

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 2007 - 2016 Microchip Technology Inc.

TABLE 4-2:

SMBUS OR EEPROM INTERFACE BEHAVIOR

CFG_SEL2

CFG_SEL1

CFG_SEL0

SMBus or EEPROM Interface Behavior

X

0

0

Configured as an SMBus slave for external download of user-
defined descriptors. SMBus slave address is 0101100

X

0

1

Configured as an SMBus slave for external download of user-
defined descriptors. SMBus slave address is 0101101

0

1

0

Internal Default Configuration

1

1

0

Internal Default Configuration via strapping options.

X

1

1

2-wire (I

2

C) EEPROMS are supported,

TABLE 4-3:

MISCELLANEOUS PINS

Name

Symbol

Type

Function

Crystal 

Input/External 

Clock Input

XTAL1/

CLKIN

ICLKx

24MHz crystal or external clock input.
This pin connects to either one terminal of the crystal or to 
an external 24MHz clock when a crystal is not used.

Crystal Output

XTAL2

OCLKx

24MHz Crystal
This is the other terminal of the crystal, or left unconnected 
when an external clock source is used to drive 
XTAL1/CLKIN. It must not be used to drive any external 
circuitry other than the crystal circuit.

Clock Input 

Enable

CLKIN_EN

I

Clock In Enable:
Low = XTAL1 and XTAL2 pins configured for use with 
external crystal
High = XTAL1 pin configured as CLKIN, and must be 
driven by an external CMOS clock.

RESET Input

RESET_N

IS

This active low signal is used by the system to reset the 
chip. The minimum active low pulse is 1us.

Self-Power / 

Bus-Power 

Detect

SELF_PWR

I

Detects availability of local self-power source.
Low = Self/local power source is NOT available (i.e., Hub 
gets all power from Upstream USB VBus).
High = Self/local power source is available.

TEST Pins

TEST[1:0]

IPD

Used for testing the chip. User must treat as a no-connect 
or connect to ground.

Analog Test

&

Internal 1.8V 

voltage regulator 

enable

ATEST/

REG_EN

AIO

This signal is used for testing the analog section of the 
chip, and to enable or disable the internal 1.8v regulator. 

This pin must be connected to VDDA33 to enable the 
internal 1.8V regulator, or to VSS to disable the internal 
regulator.

When the internal regulator is enabled, the 1.8V power 
pins must be left unconnected, except for the required 
bypass capacitors.When the PHY is in test mode, the 
internal regulator is disabled and the ATEST pin functions 
as a test pin.

TABLE 4-4:

POWER, GROUND, AND NO CONNECT

Name

Symbol

Type

Function

VDD1P8

VDD18

+1.8V core power.

If the internal regulator is enabled, then VDD18 pin 54 
must have a 4.7

F (or greater) ±20% (ESR <0.1



capacitor to VSS

VDDAPLL3P3

VDDA33PLL

+3.3V Filtered analog power for the internal PLL

If the internal PLL 1.8V regulator is enabled, then this pin 
acts as the regulator input

Maker
Microchip Technology Inc.
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